Dear all

I did an experiment having 60 vertical levels using RegCM. I want to repeat the same experiment using WRF. But I couldn't get the vertical levels in sigma coordinate. In the grads descriptor file the vertical coordinate of the output(ZDEF) is given to be (zdef   60 levels     0.0   50.0   96.5  139.8  180.2  217.9  253.2  286.3  317.4  346.6  374.1  400.0  424.5  447.7  469.6  490.5  510.3  529.1  547.1  564.3  580.7  596.4  611.5  626.0  640.0  653.4  666.4  679.0  691.1  702.9  714.4  725.6  736.4  747.1  757.4  767.6  777.6  787.4  797.0  806.5  815.9  825.1  834.3  843.4  852.4  861.4  870.3  879.2  888.2  897.1  906.0  915.0  924.1  933.2  942.3  951.6  961.0  970.5  980.2  990.0). So I was wondering how could I change this to sigma coordinate(as surface pressure is not the same). I would appreciate if anyone can suggest me how to calculate the numbers in sigma coordinate.

regards,

Netsanet